1. Field of the Invention
The present invention relates to a light emitting diode (LED) assembly, and more particularly to an LED assembly incorporating a structure to prevent solder contamination when soldering electrode leads of the LEDs thereof together.
2. Description of Related Art
LED have been available since the early 1960's. Because of the relatively high efficiency of LEDs, nowadays LED usage has been increased in popularity in a variety of applications, e.g., residential, traffic, commercial, industrial settings. However, when the LED is in operation, it generates a great deal of heat, which may result in the LED overheating or even malfunction if the heat cannot be dissipated timely. Therefore, so many attempts are tried in order to effectively cool the LED.
Typically, an LED assembly comprises a metal substrate and an LED mounted on the substrate. The metal substrate sequentially forms an electrically insulated circuit layer and an electrically conducting layer thereon. A plurality of vias is defined through the electrically insulated circuit layer and the electrically conducting layer to divide them into separated parts. The LED is mounted on the substrate with a base thereof adhesively attached on an exposed surface of the substrate, and two electrode leads thereof respectively secured to separated, electrically conducting pads by soldering.
In order to achieve a sufficient light output from the LED assembly, lots of LEDs are crowdedly mounted on the substrate, which renders adjacent LEDs quite close to each other. Accordingly, the separated, electrically conducting pad should be designed to be located adjacent the LEDs as close as possible for ensuring compact arrangement of the LEDs. Nevertheless, when soldering the electrode leads of the LEDs on the separated, electrically conducting pads, the quantity of solder should be controlled in an exact range, since a gap between the adjacent, separated electrically conducting pads is so small that even a little overflowing excess solder could fill it and cause the adjacent, separated electrically conducting pads to connect with each other, resulting in a short circuit. In addition, such overflowing excess solder can contaminate other part of the LED assembly.
What is needed, therefore, is an LED assembly which can overcome the above-mentioned disadvantages.